Setting pitch with a fork

[Sarah Fox]

Hi Cy,

>For one thing, if I play F2 with my left hand, and hold the fork to my
right ear, it's really hard to hear beats (I know I can >adjust F2 as needed
for a comfortable beat speed).  I found if I hold the fork over my left ear,
so that it's between my ear and >the piano, the beats are clearer.  (Is it
because the wave interference happens in the air, not in my head?  Sarah?)

GREAT thread, even tho' it probably should have an "OT" beside it by now.
LOL!!

In answer to your question (a very good one!), it doesn't matter which
routes the two sounds take; they will still beat against each other, as the
waveform phasing drifts.  This is actually a perceptual phenomen that occurs
in the nervous system, after the sounds are detected.  So however the sounds
reach your ear, your still good..

Beats can of course also be observed on an oscilloscope (or on the screen of
a computer displaying the waveform).  However, these "beats" are merely
pulsations in the waveform envelope that acoustically don't really mean
anything.  Now if the sounds and/or vibrations get really, really strong, to
the extent that the system is no longer "linear," then that's another
matter, but that's not important here.

To maximize the beat, of course it is best that the two sounds be of similar
amplitude -- with respect to how you *hear* them.  If the fork between your
teeth sound *to you* as loud as the vibrating string, then that's where you
should get your loudest beat

The fork between the teeth idea sounds sounds best.  Isn't that where a fork
belongs anyway?  I'll echo the precaution from others about hard, bare metal
against your teeth (vs., say, the heat shrink tubing).  It *will* produce
small fractures in your teeth over time.  This is also a problem with lip
and (especially) tongue piercings.  (Ick!  Ouch!)  When a person talks, the
stud rattles against the teeth, eventually fracturing them.  It's also true
that a warm fork is going to vibrate at a lower pitch.  I've read on this
list that some of you techs keep forks warmed  by putting them inside
pockets and such.  If so, then holding the fork between the teeth shouldn't
have much impact.  If anything, it would help keep the fork warm.

Hope that helps, although it sounds like you already got your answers on a
more practical level.  ;-)

Peace,
Sarah